Electric circuit making and breaking device



Aug. 11, 1936.

H. M.-ROCKWELL ELECTRIC CIRCUIT MAKING AND BREAKING DEVICE Filed May 25, 1932 2 Sheets-Sheet l HUGH M. ROCKWELL.

1936- H. MIROCKWELL 2,050, 897

ELECTRIC CIRCUIT MAKING AN D BREAKING DEVICE Filed May 25, 1952 2 Shets-Sh'eet 2 l HUGH M. ROCKWELL Patented Aug. 11, 1936 UNITED STATES PATENT OFFICE ELECTRIC CIRCUIT MAIHNG AND BREAKING DEVICE 11 Claims.

This invention relates to improvements in circuit making and breaking devices, and has particular reference to devices of this kind which are operated by applying a strain or pull to two of the elements thereof, without, however, producing any appreciable elongation by said strain.

An important object of the invention is to provide a switch of this nature which will be very simple in construction, easy to manufacture,

and which may be connected in circuit very easily and simply.

Another object of the invention is to provide a switch of this nature wherein two members may be normally arranged at an angle to one another 5 and become alined or nearly alined when a strain is applied to the two members, that is, the device tends to straighten out upon applying a strain, and the relative movement of the members produced thereby are utilized to control the contact making and breaking feature.

Another object of the invention is to provide a switch of this type which is designed particularly for use in connection with so-called stop light signals for motor vehicles and the like in which the switch is so contained in the breaking mechanism as to be actuated upon the application of power, pressure, or other force to apply the brakes.

Another object of the invention is to provide a switch of this type which is particularly adapted for use in a stop-light circuit for motor or other vehicles, so as to be actuated whenever the brake rod is strained or released when the brakes are being applied .or released.

A further object is to provide a switch of this kind which can very easily and quickly be applied to a vehicle without any changes in the vehicle itself and with a very slight amount of labor. 4O

switches for this purpose which are secured in some way to the body of the vehicle and operated by a connection leading from an element of the switch to the brake rod. This type of installation is objectionable in that it requires considerable labor to apply it to a vehicle, and the result is not satisfactory in practice for the reason that the adjustment of the brake rod will change in service and thus require a readjustment of the connection with the switch in order to cause the same to continue to operate properly.

The new switch herein disclosed is free from this objection, and has no portion which requires 55 to be secured to a stationary part of the vehicle,

Heretofc-re it has been customary to provide and therefore does not get out of adjustment due to any changes of the adjustment of the brake or the brake rod.

For a better understanding of my invention, I shall herein describe several embodiments thereof which constitute what I now believe to be preferred forms of the device, and shall illustrate said embodiments of the invention in the accompanying drawings, wherein:

Figure 1 is a partly sectional vertical elevation of a clevis adapted for use in a brake rod and comprising one form of switch.

Figure 2 is a top plan view of the device illustrated in Figure 1.

Figure 3 is anend view thereof, as seen from the right-hand end, the brake rod being shown as broken away in each of these three figures.

Figure 4 is a partly sectional vertical elevation of a slightly modified form of clevis and switch.

Figure 5 is a similar partly sectional vertical elevation of a still further modified form thereof, and

Figure 6 is a diagrammatic view of one form of my improved switch as applied to the braking mechanism of a suitable vehicle.

It will be understood that certain features have been illustrated in certain of these figures, but that nevertheless many of the features shown in any one of these figures may also be present in the others, and are not shown, merely to simplify the drawings and avoid confusion and undue prolixity.

Upon referring to the drawings, the diagrammatic view Figure 6 will illustrate one, form of application of my improved switch to the braking system of any suitable. vehicle. The switch may be located at any point within the braking mechanism, but in Figure 6 I have shown it applied at the forward end of the brake rods or levers, although it is within the scope of my invention to locate the switch at either end of the brake rod or rods or intermediate thereof so that it might be said to float in the middle of the rod rather than at either end.

In Figure 6, Z represents a suitable brake lever or pedal, Y the brake, X the switch mechanism, W the battery, U the signalling unit or lamp, and T the wiring. This diagrammatic View is conventional, showing the lamp grounded on the vehicle.

The brake lever or pedal may be pivoted as at Z and the brake leverage S connecting the brake Y with the lever Z may be pivotally con nected to the lever Z at X.

Referring now more particularly to Figures 1, 2, and 3 of the drawings there is illustrated a clevis comprising a substantially U-shaped element I having two arms 2 and 3 which may be provided with alined apertures i and 5 adapted to receive a portion of the brake pedal or the like which is adapted to receive a portion of the brake pedal or the like which is adapted to actuate the brake. Within the clevis may be located a square or other polygonal shaped nut or sleeve element 6 which may be connected to the brake rod 8 in any suitable manner. One manner of connecting the brake rod with the sleeve element 6 is by internally threading the sleeve element as best shown in Figure 4 to receive the threaded end I of the brake rod. This manner of connecting the sleeve element 6 with the brake rod 8 permits relative adjustment which may be accomplished by rotating the element I5 and the screw threaded end I of the rod 8 relative to each other, and the parts may be secured in adjusted position by tightening a suitable lock nut 9. It is preferable to make the element 5 square or other than round in cross section, so that in screwing the brake rod into it and jamming up the lock nut 9 it will be prevented from turning within the clevis. It may be desirable to prevent the threaded end i from being screwed too far into or through the said sleeve 6 and one way of obtaining such prevention is by making the threads in the elements 6 imperfect at its inner end III so that the threaded end I will jam and thereby prevent the end I from entering too far into the sleeve or element 6.

This is desirable in connection with the present construction because otherwise the rod 8 might project too far beyond the inner end of the sleeve 6 and interfere with the proper operation of the device.

It will be understood that while the screw threads are illustrated only in detail in Figure 4, the construction of the element 6 may be substantially identical or similar in this respect in all the forms.

It will be noted that the outer end of the sleeve 6 in each case has a portion formed as a zone or a sphere, and designated by reference character II], which cooperates with a corresponding portion or seat II formed adjacent an aperture l2 in the end of the U-shaped member I. An important feature which may be mentioned at this time is that it is advantageous to harden the end of the member 6 at the portion II! thereof, so as to minimize wear of the said spherical zone portion in service. The center of the sphere of which the said zone forms a part is located at I3, and it is desirable to maintain it at such point. Now by hardening the portion I0, while leaving the cooperating portion II of the member I in a softer condition, it is clear that most of the wear will come on the portion II. When the seat II in the clevis strap is first made, for manufacturing advantages it may be desirable to make it on an angle or bevel rather than on a radius. Of course eventually a radius or cavity will be formed at this point to conform with the spherical zone A, due to the wear of the softer material.

With the construction illustrated, it is clear that the element 6 may pivot within its seat I I about the said center I3, and that if a strain be applied between the U-shaped element I and the brake rod 8, such pivoting will occur in the efiort to make the two"center lines A and B of the U-shaped member and the brake rod coincide or aline with one another, that is, to straighten out.

Upon pivoting about the center I3, it is clear that the inner end I4 of the sleeve 6 will move upwardly, and this motion is used to control the circuit making and breaking mechanism. This mechanism is in fact the only important difference between the three embodiments of my invention illustrated and described in the present case.

In the form shown in Figure l, I provide a member I5 which in cooperation with the inner end of the U-shaped member I, will form a casing for enclosing the switch mechanism in a substantially tight manner. The member I5 as will be seen from Figures 1, 4, and 5 is itself substantially U-shaped and is arranged to cooperate with the arms 2 and 3 of the U-shaped member I to provide a substantially rectangular prism to act as a casing to protect the switch mechanism from injury and from grease and dirt and the like in service.

In order to assist in making a tight casing, it will be noted that the member I5 has a portion I6 which fits snugly between the arms 2 and 3, and also has upper and lower portions I? and I3 respectively which are made wider than the portion I6, but which are spaced apart vertically a distance substantially equal to the vertical dimension of the U-shaped element I, so that they will fit snugly against the upper and lower edges of the arms 2 and 3 of said element I, and overlap the space between them. A portion I9 at the end of the member I5 is bent at right angles to slip over the rear end of the U-shaped member I, as shown in all the figures.

The member I5 has apertures 2c and El in its top portion to allow the hollow members 22 and 23 to pass through the same without coming into electrical contact with the metal thereof. These members may be hollow tubular rivets and may be insulated from the metal above and below by strips of insulating material 25 and 25. Each of the rivets is threaded internally as shown in the sectional views in Figure 4. Here again the lower portion of the thread in each rivet is made imperfect, to prevent the screws 26 and 21 from penetrating too far downward through said rivets, which might produce disturbances in, or even prevent, the proper operation of the switch, as will be clear when the invention is fully understood hereinafter.

Referring now to Figure 1 in particular, there is shown a spring made of conducting material 28, which is secured, together with an additional spring 29, under the lower head of the rivet 23 as shown. The spring 28 has its left-hand end bent upwardly nearly into contact with the lower end of the tubular rivet 22, but normally not in actual contact therewith. The spring 29 is perforated at 3i as shown, and an insulating rivet shaped member 32 has its shank 33 inserted through said perforation 3i and its head, which is substantially hemispherical as shown, directed downwardly into contact with the member 34 which is attached to the sleeve element 6. A conductor 35 is secured to the tubular rivet 22 by means of the screw 26 and a conductor 36 is secured to the tubular rivet 23 by means of the screw 27. The conductor 35 leads through a lamp 38 and a conductor 39 to one terminal of the battery 40, which may be and usually is the ordinary battery of the vehicle, and the circuit is then completed through the other terminal of the battery i0 and the conductor 36, and

thence through the contact spring 28 and through the other tubular rivet 22 back to the conductor 35, provided said end 36 of the spring 28 makes contact with the lower end of the rivet 22.

Such contact is made between the end 30 of the spring 28 and the lower end of the rivet 22 whenever the sleeve element 6 pivots upward to a sufiicient extent about its pivot I3, to bring it about. It is obvious that only a slight upward movement of the end I4 of the member 6 is.

necessary to bring the end 36 of the spring 28 into contact with the bottom of the rivet 22, but that the member 6 is capable of a consider: ably greater amount of upward motion than is necessary to accomplish the desired result. For this reason it is very desirable to provide the bent end 30 on the spring 28, so as to permit considerable excess motion without injuring the spring. The member 34 which cooperates with the head of the rivet shaped member 32 may be of any suitable material but preferably made of insulating material if member 32 and the spring 29 are made of conducting materials. It is preferable to make the member 32 of insulating material, in which event the insulating member 34 may be entirely dispensed with.

An additional spring, preferably helical, as shown at 46, is preferably also provided to cause the member 6 to move downward in the casing about its pivot point I3, when the strain on the brake rod is relieved, so as to assure the opening of the contact between the portion 36 of the spring 23 and the lower end of the rivet 22. This spring 46 also offers resistance so that a predetermined load is required to close the contacts. In order to properly guide and position said spring 46, guide elements 44 and 45, which also are substantially rivet shaped, may be inserted within the two ends of the spring 46 as illustrated, with the curved head portions of such members 44 and 46 seated in correspondingly curved seats 41 and 48 provided in the casing member I5 and in the tubular nut 6 respectively as illustrated.

In order to assist in providing a sufficiently tight enclosure or casing for the switch mechanism described above, it will be noted that the casing member I5 has overhanging portions at its upper and lower edges, as'shown at 48, 49, 50, and SI respectively, said portions thus overlapping the upper and lower surfaces of the cooperating U-shaped casing member I as illustrated, to more eifectively seal the casing against the entrance of foreign substances.

While the form just described is the preferred form of the invention, it is possible to modify the construction in certain respects, and still provide a satisfactory device. One such modified and simplified form is illustrated in Figure 4, which operates in exactly the same way as the previous form as far as its mechanical operation is concerned, but wherein the electrical and other mechanism within the casing is simplified.

Referring now in detail to Figure 4, it will be noted that the casing formed of the elements I and I5 is practically the same as that illustrated in Figure 1, with the exception that in Figure 4 the bulged portion 41 is omitted. This is due to the fact that the spring 46 and its cooperating parts are omitted in the Figure 4 form, for which reason also the seat 48 formerly appearing in the-nut 6 is omitted and the member 34 may therefore extend the entire length of the member 6 within the casing as shown. In

this form of the invention the spring structure is simplified and instead of having the two springs 28 and 29 employed in Figure 1 form, I here provide a spring 42 having its left end bent slightly upward as shown, so as to come into close proximity to the lower end of the tubular rivet 22, in readiness to make contact therewith as soon as it is deflected upward to a slight extent by reason of the pivoting movement of the member 6. In order to provide a certain amount of additional motion of the tubular nut 6, after the contact has been made between spring 42 and rivet 22, an additional resilient member 43 may be provided below the spring 42, the left end of said member 43 hearing against the insulating strip 34 carried by the upper surface of the member 6, said spring 43 being substantially straight throughout the greater part of its length. Both of these springs 42 and 43 are preferably secured in electrical contact with the tubular rivet 23, by being held between the lower end of said rivet and the strip of insulating material 25, the construction in this respect being the same as that in Figure 1.

In the Figure 5 form, which is still more simplified, only a single spring 4I is employed instead of the composite springs used in. the types of Figures 1 and 4. In this embodiment of the invention it will be noted that the greatest simplicity prevails, inasmuch as the restoring spring 46 of Figure 1 has been eliminated as well as the above mentioned companion spring which would otherwise cooperate with contact spring 4!. This form, while the simplest of all, will still be found satisfactory in all respects, and affords the advantage of cheap-ness and simplicity in manufacture.

In Figures 4 and 5 the holes 4 and 5 are purposely placed cit-center with respect to the U- shaped member I, so as to increase the difference of alinement of the axes A and B and thus provide an increased degree of movement of the nut 6 with respect to the casing when the brake rod 8 is put under strain. This may be a desirable feature in certain cases.

In operation, the clevis constituting the present invention, and embodying an electrical switch, is inserted in the brake rod of the vehicle in place of the standard clevis previously located therein, and connections are made through a suitable battery such as 46 and a suitable sig nal such as 36 which may be a lamp or other alarmdevice, to the two tubular rivets 22 and 23 located upon the clevis.

Considering now the Figure 1 type, and-assuming that the device has been installed in the vehicle or the like, it will be noted that when no force is being applied to the pedal or other operating means of the brake rod, said rod 8 will assume substantially the position shown in to the normal operation of the vehicle, when the brake is released. Upon applying a strain to the brake rod 3 by pressure upon the brake pedal or other brake actuating device, the result will be that the brake rod 8 will tend to straighten This corresponds out or bring the two lines A and B into alinement with one another. In accomplishing this result; it is obvious that the nut 6 must pivot about the center l3, which is the center of the sphere of which the spherical zone 10, forming the seating portion of the element 6, is a, part. Upon thus pivoting about the point [3 there must be relative upward movement between the left-hand end M of the member 6 and the casing formed by the U-shaped member I and the cooperating member i5, whereby the strip of insulation 34 carried by said nut '5 will force the spring end 30 of the spring 28 against the lower end of the. rivet 22, to make contact. Upon further straining the brake rod 8, the end M will rise still higher in said casing, but the contact between 39 and 22 will remain unbroken, and the additional motion will be taken up by flexure of the springs 28 and 29, so that no permanent deformation of the springs or any other parts of the mechanism will result. The spring 46 will of course also be compressed, and will store up sufficient power to assure the end Id of the member 6 again moving downwardly when the pressure on the brake pedal is released, so as to assure again breaking the contact and putting out the light 38.

It will be obvious that the spring 4% offers resistance to the engagement of the contacts when the switch is being operated so that a predetermined pressure is required to make contact. This will insure against the switch being operated by the weight of the brake pedal or for any other such cause. The screw threads 1 upon the brake rod 8 will provide a proper adjustment of the length of said brake rod, in cooperation with the threads in the nut 6, and the lock nut 9 will serve to secure said elements in their adjusted position, in the well-known manner.

In the form shown in Figure 4, provision is made for taking up a certain amount of excess movement of the left-hand end of the nut 6 by reason of the bent end of the spring 42, in cooperation with the straight spring 63, but in this embodiment no separate or additional restoring means is provided to positively assure the disengagement of the contacts, as the flat spring itsch is designed to perform this function. In other words, the flat spring 43 acts as a resistance and restoring means and is relied on to assist in the separation of the contacts when the strain on the brake rod is discontinued.

In the form shown in Figure 5 wherein the construction is simplified as much as possible, no lost motion or excess movement of the inner end. it of the nut 8 is provided ion-and the parts are so designed that spring 4! will ofier resistance to pedal pressure and will make contact with the lower end of the rivet 22 only slightly before the lines A and B have come substantially into alinement with one another whereas in the preceding forms contact is produced long before such alinement occurs. In this respect the Figure 5 form may be simpler, but nevertheless will be found entirely satisfactory in many cases, especially where economy is necessary.

Having now described my invention and disclosed several embodiments thereof in the present specification and drawings, I desire it to be understood that such disclosures are merely illustrative, and are not to be considered as limiting my invention in any way to the details disclosed therein, for it is obvious that many changes can be made without departing from the invention. Said invention is therefore to be limited only by the following claims:

1.A clevis comprising two U-shaped members interlocked with one another to provide a casing, and an internally threaded member having a convex spherical zone near one end thereof, said casing having a cooperating seat formed therein, to receive and seat said threaded member, the threaded member and the casing having their axes normally out of alinement with one another, whereby said member will automatically pivot about the center of the spherical portion, when a strain is applied to the clevis and the member, thus causing the end of the member to move laterally in the casing, and electrical circuit controlling means located in said casing and controlled by said movement.

2. A circuit making device comprising an enclosing casing, a member movably seated therein, and a pair of contacts controlled by said movable member, said movable member being arranged to pivot as a unit about a point within the casing and thereby closing the circuit through the contacts, means whereby said member will pivot about said point when a force is applied in the direction of the longitudinal axis of said member, and means for restoring the parts to circuit breaking position when the force is removed.

3. A switch device for electrical signalling means adapted to be insulated in a brake rod, and comprising two elements which are normally out of alinement with one another, for transmitting the tension applied to the brake rod, whereby said two elements will become substantially alined with one another when such tension is applied, and switch means controlled by said elements to make and break a contact thereby due to the resulting relative motion.

4. A clevis mounted in a brake rod and comprising two relatively movable parts normally out of alinement, and a switch controlled by said parts so as to be actuated by relative motion tending to aline the parts.

5. A switch mounted in a clevis, and forming a part thereof, comprising a nut adapted to cooperate with the end of a brake rod and having a spherical seat cooperating with a correspondingly formed seat in the clevis, whereby said nut may pivot about the center of the sphere, with respect to the clevis, to control and actuate the switch, and a restoring spring cooperating with said nut and with the clevis to return the nut to its initial position when the deforming braking force ceases to act.

6. A switch for a stop-light mounted within a clevis for a brake rod said clevis having a tilting motion relative to the brake rod, and having apertures at one end thereof to receive and cooperate with the actuating means for the brake, said apertures being located a considerable distance above the center line of the clevis so as to provide a correspondingly greater difference of direction of the axes of the clevis and of the brake rod which cooperates therewith and means carried by the brake rod for actuating the switch.

7. A switch comprising two members normally disposed at an angle to each other and con structed and arranged to become alined when a strain is applied to the two members, and contacts carried by the members for engagement when said strain is applied to the members.

8. A switch for a stop light located within a portion of the brake rod system for a vehicle, and comprising two members relatively movable and normally at an angle to each other, said switch being operable by the application of a strain, pull and the like, to the brake rod system tending to aline the two members, without producing any appreciable elongation of the brake rod system.

9. A switch for a stop light mounted within a clevis of a brake rod system comprising a U- shaped member cooperating with the clevis to form a casing having contacts, a member forming part of linkage within the casing and relatively movable with respect to the casing, said member having a spherical seat cooperating with a seat in the casing, said casing in combination with the member mounted in the spherical seat thereof forming a sealed closure for the switch mechanism,

10. A switch mounted in a brake rod system comprising a clevis having an opening in its end wall, a substantially U-shaped member interfitted within said clevis and cooperating therewith to form a casing for the switch, contacts within the casing, a contact engaging member within the casing movable relative to the casing and disposed at an angle thereto with contacts disengaged, a brake rod element attached to the contact engaging member, and a convex zone adjacent one end of the contact engaging member and seated in the opening in the clevis end to permit said contacting engaging member to pivot relative to the casing and aline therewith when strain is applied to the clevis incidental to the application of braking force.

11. A switch mounted in a clevis of a brake rod system comprising a substantially U-shaped member interfitted within said clevis and 00- operating therewith to form a casing for the switch, contacts carried by the U-shaped memher, a contact engaging member within the casing and disposed at an angle thereto when contacts are disengaged, abrake rod element attached to the contact engaging member, and a convex zone engaging member adjacent one end of the contact engaging member and seated in an opening in the clevis to permit said contact engaging member to rock relative to the casing and aline therewith when strain is applied to the brake rod system and engage the contacts.

HUGH M. ROCKWELL. 

